<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>变量和常量</title>
</head>
<body>
<script>
    let countTempC = 10;//即便赋的值是integer;但 count仍然是double类型
     console.log(countTempC);
    let countTempC1;
     console.log(countTempC1);
    let room1 = "rommA",room2 = "romB";
     console.log(room1,room2);
//    常量只能被赋值一次,常量用const定义
    countTempC = 37;
    console.log(countTempC);
    //常量的名字特点：所有名字大写，下划线拼接
    const COUNT_TEMPC = 40;
    console.log(COUNT_TEMPC);

</script>
</body>
</html>